I think this depends on if you believe that personality and ability comes from nature or nurture. I assume some would like their children to have traits similar to their own which could include personality/mental health, IQ, physical health, etc. You're reasonably bounded by each parents family history.

On the other side, you may be using a donor to exclude one parents genetics, due to a known genetic issue.

Getting some random guys DNA eliminates any sort of ability for selection, which is what choosing a partner, or choosing to not reproduce with a partner, is.